Parallel-rule.



No. 791,251. PATENTED MAY 30, 1905. I I P. GUMMING. v

PARALLEL RULE.

A PPLIOATION FILED AUG. 23, 1904.

HIM'LS I. J6

WITNESSES: Z I mmvroa .PauZ Ciun nz in q- UNITED I STATES Patented m 30,1905.

PAUL CUMMING, OF KEYWEST, FLORIDA.

PARALLEL-RULE.

SPECIFICATION forming partof Letters Patent N 0. 791,251, dated May 30,1905.

I Application filed August 23, 1904. Serial No. 221,821.

1'0 all whom it may concern.-

Be it known that 1, PAUL OUMMING, a citizen of the United States,'and aresident of Keywest, in the county of Monroe and State of Florida, haveinvented a new and Improved Parallel-Rule, of which the following is afull, clear, and exact description.

My invention relates to parallel-rules, its principal objects being toprovide for various adjustments in such a device and for the lifting ofone blade while the other remains upon the work.

It consists in the various features andcombinations hereinafterdescribed and claimed.

Reference is to be had to the accompanying drawi ngs,forming a part ofthis specification, in which similar characters of referenceindicatecorresponding parts in all the figures.

Figure 1 is a perspective view of one embodiment of my invention. Fig.2' is a horizontal section therethrough, taken in the plane of thelinks. Fig. 3 is a transverse section through the blades on the line 3 3of Fig. 2, and Fig. 1 is a top plan view of a portion of another form ofmy invention.

The numerals 10 10 designate the blades of a rule, to .each of which isattached a suitable number of spherical members or balls 11, (here shownas two,)' they being maintained at some distance from the faces of theblades by stems 12, which may be riveted or otherwise secured near theirends. These balls are situated at different distances from each end ofthe rule and are connected by inclined links L, which are preferablyformed in sec-. tions, of which Figs. 1 to 3 of the drawings show four.These comprise main sections or bars 13 and 14:, the former havingthreaded openings to receive screws 15, which pass through slots 16,extended longitudinally of the bars 14. This permits these sections tobe moved over one another to vary the lengths of the links, they beingclamped in their ad justed position by turning down the heads of thescrews into contact with the sections 14. At the outer extremity of eachof the sections is shown a substantially hemispherical socket 17 to fitone of the balls, and with this is associated a similar socket member18, having a shank 19, which may be riveted to each of the 5 members 13and 14 beyond the end of its companion member. Each of the shanks 19 iscut away at 19 to leave a space between the halves of the socket.Threaded into the bar 13 and into one of the shanks 19 and passingthrough openings in the other shank 19 and the bar 1%, respectively, arescrews 20 20, by which the portions ofthe socket may be drawn toward oneanother and into more or less firm contact with the balls to vary theresistance to movement.

The sockets overhang the balls somewhat to. prevent disengagement, butstill leave sufiicient space between the outer edge of said sockets andthe ball-stems to allow one of the blades 5 to be moved vertically withrelation to the other blade, which is raised, swinging about the ballsof the fixed blade, the latter being held upon the work. This capabilityof movement of either blade with relation to the other 7 O is indicatedby dotted lines in Fig. 3 and may amount to substantially forty-fivedegrees. The variation in the lengths of-the links permits the relationof the blades to be maintained in constant parallelism, while the changein the tension or force of engagement of the socket portions upon theballs enables the wear in the joints to be taken up and any desiredresistance to movement secured.

Fig. 1 shows a link having but two sections,

21 and 22, the former being of greater thickness and cut away at itsends to leave spaces at 23. Each section carries at its ends oppositehemispherical sockets 24, which may be drawn toward one another byscrews 25 to 5 vary the tension of the joints. The sections arepreferably riveted together, there being no adjustment for the length ofthe links.

Having thus described my invention, I. claim as new and desire to secureby Letters Patent 9 1. A parallel-rule comprising blades, sphericalmembers fixed to the blades, sectional links having divided socketscoacting with the spherical members, and means for adjustably securingthe link-sections.

2. A parallel-rule comprising blades, spherical members fixed to theblades, sectional links having socket members coacting with thespherical members, socket members provided with shanks secured to thelinks, and means for adj ustably securing the link-sections.

3. A parallel-rule comprising blades, spherical members fixed t0 theblades, links having divided ends provided with substantiallyhemispherical sockets coacting with the spherical members, screwsextending through one of the divided ends and being threaded into itscompanion, and means whereby a variation in the lengths of the links ispermitted.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses. PAUL CUMMING.

l/Vitnesses:

J. M. Pmrrs,

A. W. MORRELL.

